The field of this invention relates to irrigation equipment and more particularly to irrigation equipment that provides for drip irrigation of trees, shrubs or the like.
Irrigation is the artificial watering of crops so that they achieve their full potential growth. Probably the oldest method of irrigation is flooding. Flooding comprises drenching a large quantity of water on a given area and having this occur at certain time intervals until the crop is ready to be harvested. Another method of irrigation is to use overhead sprinklers from which the water fall is sprayed like rain.
The main disadvantage to both flooding and sprinkling as a form of irrigation is that no effort is made to conserve the water. In recent year it has been found that the same crop yield can be obtained through the use of distributing of a small continuous flow of water directly to the base of the tree or shrub. This small continuous flow of water is what is frequently referred to as "drip irrigation". Drip irrigation is achieving much success in the arid areas of the world where there are limited supplies of irrigation water. Drip irrigation provides for frugal use of a limited water supply.
In the utilizing of any drip irrigation system, it is necessary to utilize some sort of valve which will cause only a very limited amount of water to be discharged through the distribution conduit to the plants that are to be irrigated. These valves, in the past, have taken numerous types of configurations. Common forms of such valves of the past have worked on the principle of a screen through which only a limited quantity of water was permitted to pass, or by capillary action, or by using a flexible diaphragm within which are formed one or more small orifices. Screens easily become clogged with foreign material. Also, the same is true for capillary tubes. Not only are th diaphragms subject to clogging, but also they are known to deteriorate rapidly upon being subjected to chemicals such as fertilizers, chlorine acid and pesticides.
Because of the deficiencies of the aforementioned types of irrigation equipment, there has recently evolved a different type of emitter which works on the basis of a ball check valve. Reference is to be had to U.S. Pat. Nos. 3,746,263, 3,926,374, 3,894,688, 3,873,031, and 3,926,375 in which irrigation equipment is shown which utilizes the ball check valve in order to achieve drip irrigation. However, one of the disadvantages of the ball check valve type of drip irrigation equipment of the prior art is that each emitter only distributes water to a single distribution conduit. If a single emitter could be utilized to distribute water to a plurality of distribution conduits, the cost of installation of such equipment could be decreased since only one emitter would be required instead of a plurality of different emitters. Also, it is possible with prior art ball check valve type of emitters, that the distribution conduit could be "kinked". A kinking of a distribution conduit, when dealing with the very limited pressure of a drip irrigation system, will result in stopping of the flow of the water. Additionally, prior art emitters were not designed to easily replace existing failed equipment.